Apparatus for recovering formation wall samples from a bore hole



Dec. 3, 1968 A. W. KAMMERER, JR APPARATUS FOR RECOVERING FORMATION WALL SAMPLES FROM A BORE HOLE 3 Sheets-Sheet 1 Filed Aug. 8, 1966 INVENTOR. flea/g2 W K411045252, cle.

TORNEY,

A. w. KAMMERER, JR 3,414,069 APPARATUS-FOR RECOVERING FORMATION WALL SAMPLES FROM A BORE HOLE Dec. 3, 1968 '3 Sheets-Sheet 3 Filed Aug. 8, 1966 -Z ma.

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e Z i M m m H "m Tm United States Patent 3,414,069 APPARATUS FOR RECOVERING FORMATION WALL SAMPLES FROM A BORE HOLE Archer W. Kammerer, Jr., Fullerton, Calif., assignor of one-fifth to Jean K. Lamphere and three-fifths t0 Archer W. Kammerer, Fullerton, 'Calif.

Filed Aug. 8, 1966, Ser. No. 570,829 26 Claims. (Cl. 175-268) The present invention relates to expansible drill bit apparatus, and more particularly to apparatus for drilling and recovering formation wall samples in a bore hole.

An object of the present invention is to provide improved apparatus for drilling and recovering formation samples from the wall of a bore hole.

Another object of the invention is to provide apparatus for drilling and recovering formation samples from the side wall of a bore hole over an extended length of the hole and around its full circumference.

Yet another object of the invention is to provide apparatus for drilling and recovering formation samples from the side wall of a bore hole, in which effective recovery is made of samples ranging in size from relatively small particles to relatively gross particles of the order of several inches in their various dimensions.

A further object of the invention is to provide apparatus for drilling the side wall of a bore hole to produce samples of the hole formation and for recovering such samples in a substantially uncontaminated state. More specifically, the samples are trapped in the apparatus for elevation therewith to the top of the hole.

An additional object of the invention is to provide apparatus for drilling and recovering formation samples from the wall of a bore hole, the apparatus being lowered readily in and elevated from the bore hole and of removing bridges or other obstructions in the hole that tend to prevent its lowering to the desired location from which recovery of the samples is desired. In connection with removing the obstructions, circulation can be established through the apparatus to convey the cuttings to the top of the bore hole. However, the samples are cut from the side wall without circulating fluid through the apparatus to prevent sample contamination by the fluid.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a somewhat diagrammatic longitudinal section through an apparatus embodying the invention, as assembled at the top of a bore hole;

FIG. 2 is a longitudinal section through the apparatus disclosed in FIG. 1, with a wash pipe latch therein, and secured to a string of drill pipe, or the like, for lowering the apparatus in a bore hole;

FIG. 3 is a view similar to FIG. 2 with the wash pipe removed;

FIG. 4 is a view corresponding to FIGS. 1 to 3 and illustrating the apparatus with the baffle portion of its perforated basket structure pushed to the bottom of the basket;

FIG. 5 is a view corresponding to that illustrated in the previously described figures showing a diverter tube and retractable plug in place for effecting expansion of the cutters of the apparatus;

FIG. 6 is a view similar to FIG. 5 illustrating the "ice cutters in their expanded condition and enlarging the diameter of the well bore to produce samples from the side wall which will drop into the basket;

FIG. 7 is a view similar to FIG. 6 with the basket filled with sample cuttings and with circulation taking place to clean the cutters without contaminating the samples;

FIG. 8 is a view similar to FIG. 7 showing the cutters shifted to their retracted position; and

FIG. 9 is a view of the apparatus at the top of the well bore and illustrating the manner of recovering the sample from the basket.

The apparatus illustrated in the drawings is adapted to be lowered in a bore hole B to a desired location and to produce samples from the side wall of the bore hole along an extended length and around its full circumference. The samples are produced by enlarging the diameter of the bore hole, being caught and trapped in a basket structure C. Once the sample retaining portion of the apparatus is filled with the cuttings, the expansible cutters 10 of the apparatus are retracted and the apparatus is elevated to the top of the hole for recovery of the trapped samples.

The upper portion A of the apparatus is constituted as an expansible drill bit, shown somewhat diagrammatically in the drawings since it is essentially the drill bit disclosed in US. Patent 2,758,819, granted to Archer W. Kammerer, Jr., for Hydraulically Expansible Drill Bits. Attention is directed to this patent for full details of the drill bit. As shown in the present drawings, the drill bit A consist-s of a mandrel 11 having an upper pin 12 threadedly connectible to the lower end of a string of drill pipe D, or other tubular string. The mandrel includes an upper kelly or drill stern portion 13 slidably splined to the main body 14 of the drill bit. The exterior 15 of the lower portion of the kelly is non-circular in shape, being telescopically received in a companion noncircular socket 16 formed in the main bit body. As an example, the kelly exterior 15 and the socket 16 may be of hexagonal shape to enable the body 14 and kelly 13 to be moved longitudinally with respect to one another while rotary movement can still be transmitted from the kelly portion 13 of the mandrel 11 to the body 14.

The mandrel 11 and body 14 have a limited range of longitudinal movement with respect to one another, upward movement of the body along the kelly being determined by engagement of an inwardly directed body shoulder 17 with the lower end 18 of the kelly portion of the mandrel. Relative downward movement of the body 14 along the kelly 13 is limited by engagement of an upper cylinder head portion 19 of the body with an annular piston 20 integral with or otherwise suitably secured to the kelly 13.

The drill bit body 14 has a plurality of expansible parts mounted on it, including cutter supporting members 21 pivotally mounted in body slots 22 on hinge pins 23 suitably secured to the body. Each cutter supporting member depends from the hinge pin and carries a toothed roller cutter 10 through suitable bearings (not shown). If desired, any other specific type of cutter may be used. The cutter supporting members 21 and the cutters 10 tend to occupy a retracted position substantially entirely within the confines of the main body 14 of the bit apparatus. These cutter supporting members and the cutters are expandable outwardly to enlarge the diameter of a bore hole and to operate upon a formation shoulder E (FIG. 6) that the cutters 10 can produce in the latter. To accomplish their-expansion, each cutter supporting member 21 has an inclined expander surface 25 on its inner portion below the hinge pin 23 which tapers in a downward and inward direction. Each expander surface terminates in a lock surface 26 formed on a lock portion 27 of the cutter supporting member. The outward expansion is accomplished by producing relative longitudinal movement between the mandrel 11 and the bit body 14, which will produce relative longitudinal movement between the cutter supporting members 21 and a lower tubular member portion 28 of the mandrel, this latter portion being slidable in a guide 29 secured to the body and extending across the body slots 22, this guide being disposed below the lock portions 27 of the cutter supporting members.

Located initially substantially above the guide 29 and below the hinge pins 23 and in cutter member recesses 30 is a mandrel lock and expander 31 which has outer portions 32 adapted to engage the expander surfaces 25 and also the lock surfaces 26. The lock and expander 31 is integral with or otherwise suitably secured to the tubular member portion 28 of the mandrel 11 which is carried by and depends from the kelly portion 13 of the mandrel.

Assuming the body 14 of the tool to be elevated relatively along the tubular mandrel 11, the inclined expander surfaces 25 of the cutter supporting members 21 will shift upwardly along the lock and expander portion 31 of the tubular member. During such upward shifting, the cutter supporting members 21 and the cutters carried thereby will be pivoted about the hinge pins 23 and urged in an outward direction. The upward movement of the body with respect to the tubular mandrel can continue until the cutters 10 have been shifted outwardly to their fullest extent, at which time the body shoulder 17 will engage the lower end 18 of the kelly portion 13 of the tubular mandrel, and the lock and expander 31 on the tubular member will be disposed behind and in engagement with the lock portions 27 on the cutter supporting members.

As specifically disclosed in the drawings, the relative longitudinal movement between the tubular mandrel 11 and the body 14 of the tool is accomplished hydraulically. Thus, the piston or enlarged portion on the drill stem 13 is received within a counterbore 35 formed in the upper portion 36 of the body of the tool, this upper portion actually constituting a cylinder having the upper cylinder head 19 extending over the mandrel piston 20 and adapted to slide relatively along the cylindrical periphery of the kelly 13 above the piston, the piston, in turn, being relatively slidable along the cylinder wall.35. A confined cylinder space 37 is formed between the piston portion 20 of the kelly, the periphery of the kelly above the piston, and the cylinder 36 and its head 19. A suitable side seal ring 38 is mounted in the piston 20 which is adapted to slidably seal against the cylindrical wall 35 of the cylinder to prevent fluid from passing in a downward direction between the piston and the cylinder. Similarly, a side seal ring 39 is mounted in the cylinder head and is slidably engageable with the kelly 13 above the piston to prevent fluid from passing in an upward direction out of the annular cylinder space 37.

Fluid under pressure in the string of drill pipe D and in the central passage 40 extending through the kelly portion of the mandrel can be fed into the cylinder 36 through one or more side ports 41 formed in the kelly and extending between its central passage 40 and the cylinder space. Such fluid under pressure can be developed by restricting or preventing downward flow of fluid through the kelly passage 40 and into a smaller diameter passage 42 through the lower portion 28 of the mandrel, there being a downwardly tapering shoulder and seat 43 provided in the tubular mandrel between the passages and below the ports. When fluid is prevented from being pumped down through the passages 40, 42, as by placing a suitable plug 44 in the tubular mandrel sealed against the wall of the kelly passage 40, as disclosed in FIGS. 5 and 6, the pressure of the fluid in the string of drill pipe D and in the kelly passage 40 can be increased. This pressure will be transmitted through the fluid in the ports 41 to the fluid in the cylinder space 37, acting upon the cylinder head 19 to urge the body 14 of the tool in an upward direction with respect to the tubular mandrel 11, securing the outward expansion of the cutter supporting members 21 and the cutters 10 to their fullest extent.

At the proper time in the operation of the apparatus, the cuttings produced by the cutters 10 will drop into the elongate perforate basket C which is secured to the lower end of the bit body 14. As disclosed, the basket is substantially cylindrical in shape and has an upper threaded pin 46 threadedly secured in the lower box 47 of the body. The lower end of the basket has a threaded box portion 48 threadedly receiving the pin 49 of a suitable drill bit P, such as a drag bit, having cutter blades 50 of a cutting diameter substantially the same as the diameter of the bore hole B in which the apparatus is to be used and, perhaps, slightly less in diameter. The drill bit F has a central passage 51 surrounded by a suitable seal ring 52 communicating with a plurality of nozzles 53 through which fluid can discharge to flush away cuttings that might be produced by the blades 50 and to convey them upwardly around the apparatus and the drill pipe D toward the top of the hole. Initially, the upper end of the basket 0 is closed by a bafile 55 extending thereacross and releasably secured to a bushing 56 by shear screws 57, or the like, the bushing being clamped between a downwardly facing shoulder 58 in the lower portion of the body and the upper end of the basket pin 46. This batfle has a central hole 59 therethrough of substantially the same diameter as the upper central passage 51 in the lower drill bit F and through which a wash pipe 60 (FIG. 2) can extend in the event that fluid circulation is to take place through the apparatus preparatory to expanding the cutters 10 outwardly.

Surrounding the body 14 of the tool below its slots 22, and spaced below the cutters 10, is an annular bridge device 61 of pliant, elastic material. Specifically, it consists of an upwardly facing rubber or rubber-like cup having an upwardly extending skirt portion 62 flaring outwardly, which is integral with a base portion 63 surrounding the body of the tool and engaging a downwardly facing shoulder 64 on the latter, the cup being held in its upward position against the body shoulder 64 by a ring 65 surrounding the body and releasably secured thereto by one or more shear screws 66. The rubber cup 61 has the purpose of deflecting and guiding cuttings and other formation sample material produced by the cutters 10 that drop downwardly of the body inwardly through the body slots 22 and toward the upper open end of the basket C after the baffle 55 has been removed, as described hereinbelow. In this connection, the drill bit body 14 defining the lower ends 67 of its slots 22 taper in a downward and inward direction to guide the cuttings toward and into the basket.

The passage 51 through the lower drill bit F can be closed by a suitable member 68, such as a ball, which will drop upon a tapered seat 69 surrounding the upper end of the passage 51. Initially, this ball 68 is held in an upward position by a cotter pin 70 extending through a hole 71 in the ball, and also through an upper hole 72 in the slotted basket, as disclosed in FIG. 1. The ball 68 is held initially in this position to enable the wash pipe 60 to be inserted through the mandrel passages 40, 42, through the central hole 59 in the baflie 55, and into the central passage 51 of the lower bit in sealing relation to the seal ring 52, the lower end of the Wash pipe terminating above the drill bit nozzles 53. The wash pipe is located in this position by virtue of its upper head 75 engaging the tapered seat or shoulder 43 in the mandrel 11, the head having a diameter conforming to the inside diameter of the kelly passage 40. The head has an upper inlet 76 for fluid which can then pass downwardly through the circulation passage 77 of the wash pipe and into the lower drill bit nozzles 53. Fluid is prevented from passing to the mandrel ports 41 for the purpose of acting upon the body cylinder 36 by spaced side seal rings 78 on the wash pipe head sealingly engaging the wall of the kelly passage 40 on opposite sides of the ports 41, as disclosed in FIG. 2.

The wash pipe 60 is releasably latched in the position shown in FIG. 2 by a suitable latch device, which, as disclosed in the drawings, can consist of an expansible split latchring 79 disposed in a peripheral groove 80 in the head and expandable partially outwardly into an internal groove 81 in the kelly below its ports 41. The outer surface of the ring 79 may taper in an upward and inward direction to permit the wash pipe 60 to be pulled upwardly, causing the ring 79 to contact the upper side of the kelly groove 81 and be retracted completely therefrom.

After the wash pipe 60 ha been assembled in the tool, as illustrated in FIG. 2, the cotter pin 70 can be pulled outwardly to release the ball 68 and allow it to drop downwardly upon the tapered upper surface 69 of the lower drill bit F, as disclosed in FIG. 2. The initial retention of the ball 68 to one side of the basket C by the cottern pin enables the wash pipe to be assembled in place, for otherwise the ball would drop across the lower bit passage 51 and prevent the lower end of the wash pipe 60 from entering it.

The apparatus is then in the position illustrated in FIG. 2 and is secured to the lower end of a string of drill pipe D to be lowered thereby in the bore hole B to the desired location at which the wall sample is to be obtained. As assurance that the cutters will remain in their fully retracted condition substantially entirely within the confines of the bit body 14, the latter is releasably secured to the mandrel 11 by a plurality of shear screws 85. This relative upward position of the mandrel with respect to the body also causes a shoulder 86 on the mandrel to engage the inwardly directed nose portions 87 on the cutter supporting members 21 to prevent the cutter supporting members and cutters 10 from swinging outwardly inadvertently.

During the lowering of the apparatus in the bore hole if bridges or other restrictions are encountered, they can be removed by rotating the drill pipe D and the entire apparatu while fluid is circulated down through the pipe D, passing through the wash pipe circulating passage 77 and discharging from the lower drill bit nozzles 53 to flush the cuttings away and convey them upwardly around the apparatus. At this time, the fluid under pressure cannot enter the cylinder space 37 of the bit through the ports 41. Following removal of the bridge, lowering of the apparatus, on the drill pipe continues until the location is reached in the bore hole at which samples of formation material are to be obtained from the wall of the hole. A suitable fishing tool (not shown) is lowered on a wire or sand line (not shown) down through the drill pipe D to be coupled to the fishing head 88 at the upper end of the wash pipe 60, whereupon an upward pull is taken on the line to retract the latch 79 from the mandrel groove 81, which releases the wash pipe from the mandrel and permits it to be pulled upwardly from the apparatus and through the drill pipe D to the top of the well bore. Upon removal of the wash pipe from the drill bit passage 51, the ball 68 can roll down the tapered surface 69 and across this passage 5-1 to close the latter and form an imperforate barrier across the lower end of the slotted basket C, the apparatus then being in the condition disclosed in FIG. 3.

It is then desired to open the upper end of the basket. Accordingly, a push bar 90 is dropped or is lowered on a sand line (not shown), or the like, through the drill pipe D, passing through the mandrel passage 40, 42 and into contact with the baffle 55. The push bar can be jarred down against the bafile to shear the screws 57 and release the baflle from the bushing, the baflle 55 then dropping to the bottom of the basket, as shown in FIG. 4. The push bar 90 is then elevated from the apparatus and through the drilling string D to the top of the bore hole.

A diverter tube 91 is then dropped into the drill pipe, followed by the retrievable plug 44. The diverter tube has an upper head 92 which will come to rest upon the mandrel seat or shoulder 43, the tube having an open upper end and a closed lower end 93 above which are located a plurality of side ports 94, so that fluid can discharge laterally outwardly from the tube passage 95 toward the Cutters 1%). The retrievable plug 44 has a lower portion 96 conforming in diameter to the diameter of the passage 40 through the kelly 13 which will come to rest upon the diverter tube 91, being a separate member from the latter. Its lower portion carries one or a plurality of side seal rings 97 adapted to seal against the wall of the kelly passage 40 below the latch groove 81, the plug having an upwardly extending neck 98 terminating in a retrieving head 99.

After the plug 44 has come to rest upon the diverter tube 91, with the latter engaging its companion shoulder 43, the drill pipe D and the entire apparatus are rotated, the drill pipe being filled with fluid (if it does not already contain fluid). Pressure is built up in such fluid, which pressure will be exerted through the ports 41 upon fluid in the cylinder space 37. When the pressure becomes sufficient to shear the screws 85, the body 14 will elevate along the mandrel 11, causing the cutter supporting members 21 to move upwardly along the lock and expander 31 of the mandrel and be urged in an outward direction. Sufficient pressure i imposed upon the fluid to cause the cutters 10 to penetrate into the wall of the hole, while rotation of the drill pipe D and the apparatus continues. As the cutters 10 penetrate further into the wall of the hole, the body 14 moves upwardly to a further extent along the mandrel 11 until the cutters 10 have been fully expanded, as determined by engagement of the body shoulder 17 with the lower end 18 of the kelly and by the fact of positioning of the lock and expander 31 behind the lock portions 27 of the cutter supporting members. The cutters have then expanded outwardly to enlarge the bore hole to the diameter H, the annular shoulder E having been produced in the formation. Rotation of the drill pipe and apparatus can continue with suitable downweight being imposed upon the cutters 10, the expander and lock 31 holding the cutters locked in their outward position. The maintenance of pressure on the fluid in the drill pipe D and in the tool A may or may not be necessary to insure the retention of the cutters in their outward position. With the appropriate drilling weight imposed on the cutters 10, and the apparatus being rotated at the proper speed, the wall of the well bore is enlarged while the tool is gradually lowered, the formation material produced by the cutters dropping downwardly, the rubber cup 61 engaging the wall of the smaller diameter bore hole B below the enlarged hole portion H and diverting the cuttings inwardly through the body slots 22 and into the upper end of the basket C, the cuttings dropping down into the basket, as indicated in FIG. 6. A sufficient length of hole is enlarged to fill the basket, at which time the cutting operation is stopped so that none of the formation cuttings will be lost.

Through use of a suitable fishing tool (not shown) lowered down through the drill pipe D, the retrieving head 99 of the plug is grasped and the plug elevated through the drill pipe to the top of the hole. If desired, circulating fluid can now be pumped down the drill pipe D and will pass into the diverter tube 91, discharging laterally through its side ports 94 toward the cutters 10 for the purpose of washing the cutters and cleaning the tool. However, the circulating fluid is not directed downwardly, so that the sample collected in the basket C and within the body portion below the slots 22 will be protected and retained (FIG. 7).

The circulation of fluid is then discontinued. Assuming the bore hole to have a relatively low fluid level, the fluid in the drill pipe D can then drain out through the diverter tube 91 into the bore hole. The cessation of pressure,

however, will then permit the drill pipe to be elevated and move the mandrel 11 upwardly within the body 14, the expander and lock shifting upwardly out of contact with the lock portions 27 of the cutter supporting members to a position opposite the recesses 30, permitting the cutters to swing inwardly to a retracted position. If the cutters do not move inwardly by gravity, the shoulder 86 on the mandrel will engage the inwardly projecting portions 87 of the cutter supporting members 21, swinging them upwardly and the cutters inwardly until the mandrel piston engages the cylinder head 19, at which time the parts are in the position illustrated in FIG. 8. The tool can now be elevated in the bore hole B to the top thereof, with the formation sample S retained within the basket C. During the upward movement, the rubber cup 61 will probably be torn from the tool.

The apparatus can then be placed over and partially into a suitable container 100 having a bit breaker 101 in the bottom portion thereof, the lower drill bit F being placed partially within the bit breaker to prevent its rotation (as is well known in the art). Suitable tongs (not shown) are placed upon the basket C to rotate the apparatus to the left and unscrew the basket from the lower bit, elevation of the apparatus from the bit F permitting the sample S within the basket to drop into the box 100 (as disclosed in FIG. 9).

The drill pipe D may then be disconnected from the mandrel, and a suitable extracting tube (not shown) moved into the mandrel and latched onto the upper end of the diverter tube 91 to remove the latter in an upward direction from the tool.

If the formation is radioactive, the sample obtained will also be radioactive, in which event it is desirable to have the box 106 lined with lead to prevent injury to personnel. At the top of the well bore, the apparatus is washed clean, the basket C is then unscrewed from the body 14 of the tool, and the packing cup stub is removed, since the main portion of the packing cup, as indicated above, would tear off during elevation of the apparatus in the bore hole incident to its removal therefrom.

The tool can now be reconditioned by the use of new shear screws 85 again initially securing the body 14 of the tool to the mandrel 11, a new packing cup 61 being mounted on the lower portion of the body, a ball 68 again pinned to the upper portion of the basket, as disclosed in FIG. 1, a baffle assembly 55, 57 being placed on top of the basket C, the basket then being attached to a bit F, as by use of the bit breaker 101, or another bit breaker, the latter also being used to threadedly secure the basket C to the lower end of the body 14, clamping the baflle device 55, 56, 57 between it and the body, the parts then being disposed in a relative position disclosed in FIG. 1. The wash pipe 60 can again be lowered in the tool and latched in place and the ball 68 released, dropping to the bottom of the basket, as disclosed in FIG. 2. The apparatus is now conditioned for attachment to the drill pipe D and lowering in the bore hole B.

By use of the apparatus, formation samples around the entire circumference of the bore hole can be obtained, and over an extended length. By way of example, the enlarging of the well bore over a length of about 8 feet has produced cuttings that will fill the slotted basket C, whereupon the tool is removed from the well bore and redressed so that an additional length of formation sample can be obtained, if desired. The apparatus is capable of securing cuttings over a wide range of particle size, from relatively small particles that preferably will not pass through the basket slots T, which can be made relatively narrow if desired, to those of rock size capable of being held in the hand, which, for example, may be several inches in length and also several inches in a lateral dimension. The opening in the upper end of the batsket C is large enough to receive such large size samples of the formation material.

I claim:

1. In apparatus for cutting and retrieving formation samples from the wall of a bore hole: a rotary drill bit adapted to be lowered in the bore hole and having initially retracted cutter means expandable laterally outwardly to produce cuttings from the wall of the bore hole and to enlarge the diameter of the bore hole incident to rotation of the drill bit and its cutter means; and formation collecting means secured to and depending from the lower portion of said drill bit and having an upper opening through which the cuttings can drop into the formation collecting means; said rotary drill bit having means for connecting said bit to tubular drill string means extending to the top of the well bore and also having a longitudinal passage communicating with the tubular drill string means for conducting fluent material between said drill bit and the top of the well bore.

2. In apparatus as defined in claim 1; and a drill bit secured to the lower portion of said formation collecting means.

3. In apparatus as defined in claim 1; said formation collecting means comprising an elongate perforate basket.

4. In apparatus as defined in claim 1; said formation collecting means comprising an elongate perforate basket; and a drill bit secured to the lower portion of said basket.

5. In apparatus as defined in claim 1; and annular barrier means below said cutter means engageable with the wall of the bore hole to direct the cuttings toward said upper opening.

6. In apparatus for cutting and retrieving formation samples from the wall of a bore hole: a rotary drill bit adapted to be lowered in the bore hole and having initially retracted cutter means expandable laterally outwardly to produce cutting from the wall of the bore hole and to enlarge the diameter of the bore hole incident to rotation of the drill bit and its cutter means; and formation collecting means secured to and depending from the lower portion of said drill bit and having an upper opening through which the cuttings can drop into the formation collecting means; said rotary drill bit having means for connecting said bit to a tubular drill string and also having a longitudinal passage extending therethrough; a lower drill bit secured to the lower portion of said formation collecting means; said rotary drill bit having means and fluid conducting means in said rotary drill bit passage extending through said formation collecting means to said lower drill bit to conduct fluid from the drill pipe to said fluid discharge means.

7. In apparatus for cutting and retrieving formation samples from the wall of a bore hole: a rotary drill bit adapted to be lowered in the bore hole and having initially retracted cutter means expandable laterally outwardly to produce cuttings from the wall of the bore hole and to enlarge the diameter of the bore hole incident to rotation of the drill bit and its cutter means; and formation collecting means secured to and depending from the lower portion of said drill bit and having an upper opening through which the cuttings can drop into the formation collecting means; said formation collecting means comprising an elongate perforate basket; said rotary drill bit having means for connecting said bit to a tubular drill string and also having a longitudinal passage extending therethrough; a lower drill bit secured to the lower portion of said basket and having fluid discharge means; and fluid conducting means in said rotary drill bit passage extending through said basket to said lower drill bit to conduct fluid from the drill pipe to said fluid disdischarge means.

8. In apparatus as defined in claim 7; means releasably securing said fluid conducting means to said rotary drill bit to permit removal of said fluid conducting means from said lower bit, basket and passage; and means for closing the lower end of said basket after removal of said fluid conducting means.

9. In apparatus as defined in claim 7; a pliant, elastic upwardly facing cup secured to said rotary drill bit below said cutter means and engagea'ble with the wall of the bore hole to direct the cuttings toward said upper opening.

10. In apparatus as defined in claim 7; means releasably securing said fluid conducting means to said rotary drill bit to permit removal of said fluid conducting means from said lower bit, basket and passage; means for closing the lower end of said basket after removal of said fluid conducting means; and a pliant, elastic upwardly facing cup secured to said rotary drill bit below said cutter means and engageable with the wall of the bore hole to direct the cuttings toward said upper opening.

11. In apparatus as defined in claim 7; baffle means releasably held across said upper opening; said fluid conducting means -being releasably secured to said rotary drill bit extending through said baflie means.

12. In apparatus as defined in claim 7; means releasably securing said fluid conducting means to said rotary drill bit to permit removal of said fluid conducting means from said lower bit, basket and passage; means for closing the lower end of said basket after removal of said fluid conducting means; and means adapted to be moved down the drill pipe into engagement with said rotary drill bit, after removal of said fluid conducting means, to discharge fluid laterally toward said cutter means.

13. In apparatus for cutting and retrieving formation samples from the wall of a bore hole: a rotary drill bit adapted to be lowered in the bore hole and having initially retracted cutter means expandable laterally outwardly to produce cuttings from the wall of the bore hole and to enlarge the diameter of the bore hole incident to rotation of the drill bit and its cutter means; and formation collecting means secured to and depending from the lower portion of said drill bit and having an upper opening through which the cuttings can drop into the formation corlecting means; bafiie means releasably held across said upper opening; and means for releasing said baffle means to enable said baflle means to drop to the bottom of said formation collecting means.

14. In apparatus as defined in claim 13; said formation collecting means comprising an elongate perforate basket; said rotary drill bit having means for connecting said bit to a tubular drill string and also having a 10ngitudinal passage extending therethrough; a lower drill bit secured to the lower portion of said basket and having fluid discharge means; fluid conducting means releasably secured to said rotary drill bit in said drill bit passage extending through said baflle means and basket to said lower drill bit to conduct fluid from the drill pipe to said fluid discharge means; and means for closing the lower end of said basket after removal of said fluid conducting means.

15. In apparatus as defined in claim 13; said formation collecting means comprising an elongate perforate basket; said rotary drill bit having means for connecting said bit to a tubular drill string and also having a longitudinal passage extending therethrough; a lower drill bit secured to the lower portion of said basket and having fluid discharge means; fluid conducting means releasably secured to said rotary drill bit in said drill bit passage extending through said baffle means and basket to said lower drill bit to conduct fluid from the drill pipe to said fluid discharge means; means for closing the lower end of said basket after removal of said fluid conducting means; and a pliant, elastic upwardly facing cup secured to said rotary drill bit below said cutter means and engageable with the wall of the bore hole to direct the cuttings toward said upper opening.

16. In apparatus for cutting and retrieving formation samples from the wall of a bore hole: a rotary drill bit adapted to be lowered in the bore hole on a tubular drill string, said bit having initially retracted cutter means and fluid operated means responsive to the pressure of fluid in the drill string for expanding said cutter means laterally outwardly to produce cuttings from the wall of the bore hole and to enlarge the diameter of the bore hole incident to rotation of the drill bit and its cutter means, said bit having fluid passage means communicating with said fluid operated means and with the drill string when the bit is connected to the drill string; formation collecting means secured to and depending from the lower portion of said drill bit and having an upper opening through which cuttings can drop into the formation collecting means; and plug means for closing said fluid passage means below its point of communication with said fluid operated means to enable fluid pressure to be built up in the drill pipe and passage means for action upon said fluid operated means to expand said cutter means while preventing downward flow of fluid from said passage means to said formation collecting means.

17. In apparatus as defined in claim 16; fluid diverter means in said passage means below said plug means to discharge fluid laterally toward said cutter means; said plug means being removable from said passage means through the drill string to permit fluid to pass into said fluid diverter means.

18. In apparatus for cutting and retrieving formation samples from the wall of a bore hole: a rotary drill bit adapted to be lowered in the bore hole on a tubular string, said bit having initially retracted cutter means and fluid operated means responsive to the pressure of fluid in the drill string for expanding said cutter means laterally outwardly to produce cuttings from the wall of the bore hole and to enlarge the diameter of the bore hole incident to rotation of the drill bit and its cutter means, said bit having fluid passage means communicating with said fluid operated means and with the drill string when the bit is connected to the drill string; formation collecting means secured to and depending from the lower portion of said drill bit and having an upper opening through which cuttings can drop into the formation collecting means; a lower drill bit secured to the lower portion of said formation collecting means and having fluid discharge means; and removable fluid conducting means in said passage means extending through said formation collecting means to said lower drill bit to conduct fluid from the drill pipe to said fluid discharge means, said fluid conducting means incluing means preventing flow of fluid from said passage means to said fluid operated means.

19. In apparatus as defined in claim 18; and means for closing the lower end of said formation collecting means after removal of said fluid conducting means from said passage means.

20. In apparatus as defined in claim 18; means for closing the lower end of said formation collecting means after removal of said fluid conducting means from said passage means; and plug means for closing said fluid passage means below its point of communication with said fluid operated means, after removal of said fluid conducting means, to enable fluid pressure to be built up in the drill pipe and passage means for action upon said fluid 0perated means to expand said cutter means while preventing downward flow of fluid from said passage means to said formation collecting means.

21. In apparatus as defined in claim 18; means for closing the lower end of said formation collecting means after removal of said fluid conducting means from said passage means; plug means for closing said fluid passage means below its point of communication with said fluid operated means, after removal of said fluid conducting means, to enable fluid pressure to be built up inthe drill pipe and passage means for action upon said fluid operated means to expand said cutter means while preventing downward flow of fluid from said passage means to said formation collecting means; fluid diverter means in said passage means below said plug means to discharge fluid laterally toward said cutter means; said plug means being removable from said passage means through the drill string to permit fluid to pass into said fluid diverter means.

22. In apparatus as defined in claim 18; baffle means releasably held across said upper opening and through which said fluid conducting means extends; means for closing the lower end of said formation collecting means after removal of said fluid conducting means from said passage and baffle means; and means for releasing said baflie means to enable said baffle means to drop to the bottom of said formation collecting means.

23. In apparatus as defined in claim 18; 'baffle means releasably held across said opening and through which said fluid conducting means extends; means for closing the lower end of said formation collecting means after removal of said fluid conducting means from said passage and baflle means; means for releasing said baffle means to enable said baffle means to drop to the bottom of said formation collecting means; and a pliant, elastic upwardly facing cup secured to said rotary drill bit below said cutter means and engageable with the wall of the bore hole to direct the cuttings toward said upper opening.

24. In apparatus as defined in claim 18; baflie means releasably held across said opening and through which said fluid conducting means extends; means for closing the lower end of said formation collecting means after removal of said fluid conducting means from said passage and baffle means; means for releasing said baflle means to enable said baflie means to drop to the bottom of said formation collecting means; and plug means for closing said fluid passage means below its point of communication with said fluid operated means to enable fluid pressure to be built up in the drill pipe and passage means for action upon said fluid operated means to expand said cutter means while preventing downward flow of fluid from said passage means to said formation collecting means.

25. In apparatus as defined in claim 18; baflie means releasably held across said opening and through which said fluid conducting means extends; means for closing the lower end of said formation collecting means after removal of said fluid conducting means from said passage and baffle means; means for releasing said baflie means to enable said baifle means to drop to the bottom of said formation collecting means; plug means for closing said fluid passage means below its point of communication with said fluid operated means to enable fluid pressure to be built up in the drill pipe and passage means for action upon said fluid operated means to expand said cutter means while preventing downward flow of fluid from said passage means to said formation collecting means; fluid diverter means in said passage means below said plug means to discharge fluid laterally toward said cutter means; said plug means being removable from said passage means through the drill string to permit fluid to pass into said fluid diverter means.

26. In apparatus as defined in claim 18; baflle means releasably held across said opening and through which said fluid conducting means extends; means for closing the lower end of said formation collecting means after removal of said fluid conducting means from said passage and baffle means; means for releasing said baflie means to enable said baflle means to drop to the bottom of said formation collecting means; plug means for closing said fluid passage means below its point of communication with said fluid operated means to enable fluid pressure to be built up in the drill pipe and passage means for action upon said fluid operated means to expand said cutter means while preventing downward flow of fluid from said passage means to said formation collecting means; fluid diverter means in said passage means below said plug means to discharge fluid laterally toward said cutter means; said plug means being removable from said passage means through the drill string to permit fluid to pass into said fluid diverter means; and a pliant, elastic upwardly facing cup secured to said rotary drill bit below said cutter means and engageable with the Wall of the bore hole to direct the cuttings toward said upper opening.

References Cited UNITED STATES PATENTS 1,406,348 2/ 1922 Corrigan 3 11 X 1,896,107 2/1933 Simmons 175311 X 2,058,119 10/ 1936 Williams 1753 11 X 2,344,778 3/1944 Keplinger 1753 11 X 2,585,369 2/1952 Caruthers 175-58 X 2,631,821 3/1953 Caldwell 175-311 X 2,832,568 4/1958 Kammerer 175267 X 2,930,586 3/1960 Long 1753l1 X FOREIGN PATENTS 236,078 10/1961 Australia.

CHARLES E. OCONNELL, Primary Examiner.

I. A. CALVERT, Assistant Examiner. 

1. IN APPARATUS FOR CUTTING AND RETRIEVING FORMATION SAMPLES FROM THE WALL OF A BORE HOLE: A ROTARY DRILL BIT ADAPTED TO BE LOWERED IN THE BORE HOLE AND HAVING INITIALLY RETRACTED CUTTER MEANS EXPANDABLE LATERALLY OUTWARDLY TO PRODUCE CUTTINGS FROM THE WALL OF THE BORE HOLE AND TO ENLARGE THE DIAMETER OF THE BORE HOLE INCIDENT TO ROTATION OF THE DRILL BIT AND ITS CUTTER MEANS; AND FORMATION COLLECTING MEANS SECURED TO AND DEPENDING FROM THE LOWER PORTION OF SAID DRILL BIT AND HAVING UPPER OPENING THROUGH WHICH THE CUTTINGS CAN DROP INTO THE FORMATION COLLECTING MEANS; SAID ROTARY DRILL BIT HAVING MEANS FOR CONNECTING SAID BIT TO TUBULAR DRILL STRING MEANS EX- 